Epoch Millis vs Seconds Detector
Paste a bare number or a JSON/log line. The tool guesses seconds vs milliseconds from digit length with a confidence label, shows both interpretations side by side when ambiguous, decodes microseconds and nanoseconds (with safe-integer warnings), adds relative time and ISO/local formats, scans pasted text for every epoch-looking number, flags Y2038 for 32-bit overflow, and offers one-click copy as ISO, local, or UTC.
Runs 100% in your browser — nothing you paste leaves your device.
Read the full guide to this tool
Notes
- The magnitudes are unambiguous for decades around now: 10 digits = seconds, 13 = millis, 16 = micros, 19 = nanos.
- A timestamp that decodes to 1970 in every interpretation is probably not a timestamp at all.
- Runs 100% in your browser — nothing you paste leaves your device.
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